The invention relates to a circuit arrangement made up of a plurality of luminescence semiconductor components having a forward/reverse characteristic and having control lines leading to at least one part of the semiconductor components.
Circuit arrangements of this type are used, in many cases, for analog displays. Today the speeds in vehicles, the level of fullness in containers, the desired and actual state at control panels and the matching of stereo devices is displayed by showing a variable luminous dot or a variable luminous strip. In arrangements already known, light-emitting diodes are used made of GaAsP or GaP. A plurality of light-emitting diodes is arranged for example in a line and provided with a control circuit, by means of which individual light-emitting diodes or a variable series of light-emitting diodes may be made to illuminate. When there is a change in the information to be shown, then in these known display arrangements either a luminous dot moves on a scale or the length of a luminous strip is altered. A luminous strip which may be changed and which contains the information to be reproduced may be compared for example with a thermometer while a luminous dot, which may move across a predetermined scale range, may be compared to a moving-coil instrument.
The manufacturing costs of the described light-emitting analog display are determined essentially by the number of control lines required. Furthermore, the current requirement of the display unit must be kept as small as possible and this can be attributed to the fact that only a current of limited value may be derived from an integrated control circuit.
A circuit has already become known in which the control of a line of light-emitting diodes having a total of 16 light-emitting diodes takes place by means of 8 control lines. Thus the diodes are generally connected in the form of a X/Y matrix. This circuit is provided for showing a variable luminous dot, but is not suitable for luminous strip display as the current requirement is too large when controlling all diodes.
In a known luminous strip display the current from an integrated control circuit is passed through several light-emitting diodes one after the other. Thus a control line leads to each individual diode of the whole arrangement so that a total of 17 control lines are required in order to implement a luminous strip line made up of 16 diodes--if the required earth line is taken into account. This number of lines can only be accommodated at high cost in an integrated circuit.